Month: March 2017

If the weather warms up a bit, we could see eastern tent caterpillars (Malacosoma americanum) and forest tent caterpillars (Malacosoma disstria) hatching before the next forest health newsletter. These are both early spring caterpillars and hatch very soon after bud break.

Eastern tent caterpillars with pen. Web nests and caterpillars will be small at first.

Eastern tent caterpillar will make a web nest that can often be seen on wild black cherry along roadsides, although they also like to feed on crabapple, apple, and a few other species. Forest tent caterpillar does not make a web nest and prefers to feed on aspen and oak.

If you had box elder bugs or multi-colored Asian lady beetles congregating on your house last fall, you’re probably starting to notice them appearing in your house again as the weather warms this spring. Last fall they were able to find a place on/in your house to overwinter and now they are attempting to leave your house to head back into the fields where the beetles, like all ladybugs, will feed on aphids and the box elder bugs will feed on the sap of certain trees.

BMSB is native to eastern Asia and was first officially found in the U.S. in 2001. The discovery of BMSB juveniles and the first noted pairs of mating adults in 2016 are continued signs that this invasive pest is establishing and reproducing in Wisconsin. We also had the first reports of BMSB feeding on plants, not just overwintering in structures. We expect populations will continue to increase in coming years.

A map of counties where BMSB has been confirmed or is suspected as of October 2016 was created by P.J. Liesch, University of Wisconsin-Madison Insect Diagnostic Lab and Bill McNee, Wisconsin DNR.

For information about how to identify BMSB and how to manage nuisance populations check out these publications.

There are currently two products available to treat fresh pine stumps to prevent new infections of heterobasidion root disease (HRD), which was previously called annosum. The products are Cellu-Treat and Rotstop-C. Both are water soluble and can be sprayed on the stump. Sporax, a granular/powder product, was previously available but is no longer being manufactured. If you still have a supply of Sporax you can continue to use it. The one-page factsheet on HRD (Annosum) has been updated with information on where to purchase the available products.

For more information on Cellu-Treat and Rotstop-C please check out these websites:

White balls of hemlock woolly adelgid ‘wool’ on a hemlock twig in Maryland.

If you work around hemlock trees, keep an eye out for signs of hemlock woolly adelgid (HWA), an aphid-like insect that was introduced to eastern North America and is fatal to most hemlock trees.

HWA produces distinctive, small balls of white wool at the base of hemlock needles. Recently, a number of infestations have been found in western Michigan and there is a risk that the pest could spread across Lake Michigan into Wisconsin. Hemlock woolly adelgid has not been found in Wisconsin. Continue reading “Unwanted in Wisconsin: hemlock woolly adelgid” →

Bur oak blight (BOB) was confirmed for the first time in Clark and Sawyer counties in 2016. The number of reports of symptoms of this disease was low in 2016 across its range in Wisconsin. Currently, BOB has been detected in 24 counties in Wisconsin.

Ice coating an urban tree from a late February 2017 storm in south central Wisconsin.

Several ice storms have impacted yard and forest trees in southern Wisconsin in 2016/2017. The combination of trees coated in heavy ice and strong winds caused broken branches and bent or broken main stems. Working with storm damaged trees can be very dangerous, so landowners should carefully consider safety concerns and get help from professional arborists or foresters when appropriate. Continue reading “Ice damage to yard and forest trees” →

Little damage from bark beetles was encountered in the Northwest, West Central and East Central areas. Damage in the east central counties was restricted to trees that suffered from drought in 1966. Advance reproduction was destroyed in two Jackson County timber sale areas (West Central Area) where pulp operations continued through the summer and wood was left in piles until bark beetles had emerged. Continue reading “Historical – what happened 50 years and 25 years ago in the forest health world?” →

Happy International Day of Forests! Annually, March 21 is a day dedicated to celebrating and raising awareness of our forests. This year’s International Day of Forests theme is “forests and energy.”

In a video clip titled “The forest: nature’s powerhouse,” organizers of the 2017 celebration note, “Trees store the sun’s energy by turning it into wood which has always been the world’s most used source of renewable energy. New scientific advances using wood waste are opening it up to even more uses like liquid biofuels, making it a fuel of the future.”

Recently, the DNR Urban Forestry Program and the Wisconsin Arborist Association (WAA) recently held the annual Wisconsin Urban Forestry Conference in Green Bay, Wisconsin. With the theme “Healthy Benefits to Enriching Your Arboriculture and Urban Forestry Knowledge,” the conference was three full days of exhibits, presentations from experts across the world, and networking events and opportunities. There was record attendance this year, beating out last year’s record of 750. This year, the WAA offered a new Utility Track of presentations that allowed members to learn more about technologies in community forestry and other topics to help those who attended.Continue reading “Review 2017 WAA annual conference” →